Materials Data on AlFeCuSe3 by Materials Project
CuFeAlSe3 is Stannite-like structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to four Se2- atoms to form FeSe4 tetrahedra that share a cornercorner with one FeSe4 tetrahedra, corners with five CuSe4 tetrahedra, and corners with six AlSe4 tetrahedra. There are a spread of Fe–Se bond distances ranging from 2.43–2.49 Å. In the second Fe2+ site, Fe2+ is bonded to four Se2- atoms to form FeSe4 tetrahedra that share a cornercorner with one FeSe4 tetrahedra, corners with five AlSe4 tetrahedra, and corners with six CuSe4 tetrahedra. There are a spread of Fe–Se bond distances ranging from 2.43–2.52 Å. In the third Fe2+ site, Fe2+ is bonded to four Se2- atoms to form FeSe4 tetrahedra that share corners with two equivalent FeSe4 tetrahedra, corners with five CuSe4 tetrahedra, and corners with five AlSe4 tetrahedra. There are a spread of Fe–Se bond distances ranging from 2.43–2.49 Å. In the fourth Fe2+ site, Fe2+ is bonded to four Se2- atoms to form FeSe4 tetrahedra that share corners with four FeSe4 tetrahedra, corners with four CuSe4 tetrahedra, and corners with four AlSe4 tetrahedra. There are two shorter (2.47 Å) and two longer (2.48 Å) Fe–Se bond lengths. There are four inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share a cornercorner with one CuSe4 tetrahedra, corners with five AlSe4 tetrahedra, and corners with six FeSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.44–2.49 Å. In the second Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with two equivalent CuSe4 tetrahedra, corners with four FeSe4 tetrahedra, and corners with six AlSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.43–2.49 Å. In the third Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share a cornercorner with one CuSe4 tetrahedra, corners with five AlSe4 tetrahedra, and corners with six FeSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.44–2.49 Å. In the fourth Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four FeSe4 tetrahedra, corners with four CuSe4 tetrahedra, and corners with four AlSe4 tetrahedra. All Cu–Se bond lengths are 2.44 Å. There are four inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four Se2- atoms to form AlSe4 tetrahedra that share corners with two equivalent AlSe4 tetrahedra, corners with four FeSe4 tetrahedra, and corners with six CuSe4 tetrahedra. There are a spread of Al–Se bond distances ranging from 2.40–2.50 Å. In the second Al3+ site, Al3+ is bonded to four Se2- atoms to form AlSe4 tetrahedra that share a cornercorner with one AlSe4 tetrahedra, corners with five CuSe4 tetrahedra, and corners with six FeSe4 tetrahedra. There are a spread of Al–Se bond distances ranging from 2.41–2.49 Å. In the third Al3+ site, Al3+ is bonded to four Se2- atoms to form AlSe4 tetrahedra that share a cornercorner with one AlSe4 tetrahedra, corners with five CuSe4 tetrahedra, and corners with six FeSe4 tetrahedra. There are a spread of Al–Se bond distances ranging from 2.41–2.50 Å. In the fourth Al3+ site, Al3+ is bonded to four Se2- atoms to form AlSe4 tetrahedra that share corners with four FeSe4 tetrahedra, corners with four CuSe4 tetrahedra, and corners with four AlSe4 tetrahedra. There are three shorter (2.46 Å) and one longer (2.47 Å) Al–Se bond lengths. There are twelve inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one Fe2+, one Cu1+, and two Al3+ atoms to form corner-sharing SeAl2FeCu tetrahedra. In the second Se2- site, Se2- is bonded to one Fe2+, two Cu1+, and one Al3+ atom to form corner-sharing SeAlFeCu2 tetrahedra. In the third Se2- site, Se2- is bonded to two Fe2+, one Cu1+, and one Al3+ atom to form corner-sharing SeAlFe2Cu tetrahedra. In the fourth Se2- site, Se2- is bonded to one Fe2+, one Cu1+, and two Al3+ atoms to form corner-sharing SeAl2FeCu tetrahedra. In the fifth Se2- site, Se2- is bonded to one Fe2+, two Cu1+, and one Al3+ atom to form corner-sharing SeAlFeCu2 tetrahedra. In the sixth Se2- site, Se2- is bonded to two Fe2+, one Cu1+, and one Al3+ atom to form corner-sharing SeAlFe2Cu tetrahedra. In the seventh Se2- site, Se2- is bonded to one Fe2+, two Cu1+, and one Al3+ atom to form corner-sharing SeAlFeCu2 tetrahedra. In the eighth Se2- site, Se2- is bonded to one Fe2+, one Cu1+, and two Al3+ atoms to form corner-sharing SeAl2FeCu tetrahedra. In the ninth Se2- site, Se2- is bonded to two Fe2+, one Cu1+, and one Al3+ atom to form corner-sharing SeAlFe2Cu tetrahedra. In the tenth Se2- site, Se2- is bonded to one Fe2+, two Cu1+, and one Al3+ atom to form corner-sharing SeAlFeCu2 tetrahedra. In the eleventh Se2- site, Se2- is bonded to one Fe2+, one Cu1+, and two Al3+ atoms to form corner-sharing SeAl2FeCu tetrahedra. In the twelfth Se2- site, Se2- is bonded to two Fe2+, one Cu1+, and one Al3+ atom to form corner-sharing SeAlFe2Cu tetrahedra.